1. Field of the Invention
This invention pertains generally to communication between devices which are not Internet-ready because they lack the ability to transmit information using the required Internet communication protocols. More specifically, this invention enables voice communication using a telephone where the voice signals are transmitted via the Internet as opposed to using conventional long-distance switched telephone network lines.
2. State of the Art
One of the drawbacks of trying to bring diverse technologies together is that they often do not share a common hardware foundation for their structure. This is especially true in communication technologies which typically have proprietary protocols by which data is formatted for transmission, as well as an incompatible hardware structure over which the data travels. Yet it can be the case where each of the diverse technologies offers advantages over others.
Two technologies which share the common goal of providing a conduit for communication are publicly switched telephone networks (PSTNs) and the Internet It is well known that a telephone is typically a voice communication device, but there have been successful attempts to meld facsimile and modem data communication over the same telephone lines. In contrast, the Internet until recently has been dedicated to computer data communication exclusively. Yet these technologies both have desirable characteristics (reliable and simple voice communication versus reliable and rapid computer data transmission around the world with no long-distance telephone charges) which the other technology is being crafted to crudely exploit despite the drawbacks inherent in forcing a communication technology upon a transmission medium for which it was not specifically designed.
For example, computer data transmission via a PSTN is successfully if not slowly accomplished via a computer equipped with a modem coupled to a PSTN line. Such a computer can access another computer so equipped in order to exchange information directly. The extreme disadvantage is that the caller must bear long distance telephone charges if the computers are located further apart than a local telephone call away from each other.
A slight improvement in computer data transmissions via PSTNs occurred when large services which are accessed via modem began to provide local telephone access. This was accomplished by providing local telephone numbers around many major population centers which would in turn access the service. By negotiating bulk contracts for long distance telephone rates, the service provided a way by which it could be reached without incurring the long distance telephone charges.
Despite this improvement, however, there are several drawbacks in using PSTNs to transfer computer data. For example, one of the most important limitations is that speed of data transmission is inherently inferior to dedicated computer network speeds.
As stated earlier, however, the Internet provides some unique advantages which PSTNs cannot because of the very nature of the physical transmission medium which comprises the Internet. To understand these advantages, it helps to understand some of the background behind the development of the Internet.
The military has always recognized the importance of maintaining communication lines open in all circumstances, especially in times of war. The interest of the government was so keen that it launched the DARPA project. DARPA consisted of a computer network which did not rely on any single node or cable for its existence. On the contrary, it was specifically designed to provide multiple pathways for communication to flow from a source to a destination. In this way, data can be routed along a large variety of pathways. Successful transmission of a message does not have to rely on any single pathway for the majority of the message to reach its destination. The successor to the DARPA project is now the better known and widely used Internet.
One more important distinction between a PSTN and the Internet which should be recognized is that a PSTN is typically an analog data transmission medium, whereas the Internet only transmits digital data. Despite the fact that a PSTN can in some circumstances transmit digital data, transmitting digital computer data via a PSTN typically requires translation of the data into frequency modulated analog signals. Likewise, transmitting analog voice data via the Internet requires translation of the data a digital format.
Transmitting voice data via the Internet is feasible not only because voice data can be digitized, but like PSTNs, it is a global transmission medium which substantially duplicates the PSTNs area of coverage. The motivating factor providing impetus for improving voice transmission via the Internet, however, originates with the cost structure associated with using the Internet. As is well known, a long distance telephone call incurs long distance telephone charges. In contrast, the Internet does not have long distance communication charges associated with it. This is the key to the desirability of expanding the capabilities of the Internet.
This simple cost/benefit analysis has not escaped the attention of various commercial entities trying to exploit the Internet. It is only recently, however, that commercial efforts have become viable. The reason for this viability is that the growth in the number of Internet users has grown substantially in a very short time. Our television advertising and printed media sponsors and commercial entities now often bear World Wide Web URL addresses which an Internet user can access with sophisticated but easy to use software tools. The Internet is increasingly pervasive in every-day life because the number of people using it has increased as the ability to use and access the Internet has also increased.
Providing voice transmission capabilities via the Internet has focused exclusively to date on computer users running software on a computer which has the essential accessories. These accessories are software to digitize sound and a microphone for receiving the sound to be digitized. It seems only logical that a computer serve as the conduit by which the Internet is accessed because that is the only way that the Internet is useable. The importance of that statement lies in the specific communication requirements for a device which is to communicate with other devices via the Internet. That is to say, all devices which communicate via the Internet do so using Internet communication protocols. Internet communication protocols are methods of creating packets of digital data suitable for transmission via the Internet. A person skilled in the art will recognize that the most common Internet communication protocol is the Transport Connect Protocol/Internet Protocol, or TCP/IP. In essence, a device which communicates via the Internet is a TCP/IP capable device.
In light of this background, it would be an advantage over the state of the art to be able to provide a method and apparatus for transmitting voice data via the Internet without having to have a computer which is TCP/IP capable. That is to say, it would be an advantage to talk to another person who is normally a long distance telephone call away without incurring long distance telephone charges and without requiring a computer at either end of the transmission.